Art of drying semiliquid materials



Nov. 24, 1925. 1,562,761

G. D. HARRIS EMILIQUID MATERIALS Filed 001;. 23, 1920 Patented Nov. 24, v 1925.

UNITED STATES 1,562,761 PATENTTOFFICE.

GORDON DoN' mmms, or IsLIr, NEW Ironic; AssIeNon, BY MESNE ASSIGNMENTS,

To run INDUSTRIAL DRYER CORPORATION, or STAMFORD, co NEcrIcur, A con- PORATION or coNNEcr cUr.

- ART, OF DRYING SEMILIQU ID MATERIALS.

Application filed October 23, 1920. SerialNo. 419,054. I

To aZZ whom it may concemf Be it known that I, GORDON DoN H ARRIs, a citizen of the United States, residin at Islip, county of Suifolk, and State of ew,

York, have invented a certain new and useful Art of Drying Semiliquid Materials, of which the following is a specification.

This invention pertains to the art of drying semi-liquid materials, such. as milk,

eggs, blood and food products, although it' is to be understood that the invention may be used for drying materials other those specified.

In the art of treating food substances,

such as milk, it is desirable to evaporate the moisture content so as ultimately to at-- tain a product in a pulverulent and condition, such evaporation beingeflected while maintainin the semi-liquid material in a heated con ition, the temperature of said material being constant, or substantially constant, throughout the treatment except at the period just prior to delivery, at which period the dry product is cooled, more or less.

According to this invention, the semiliquid material is spread or diffused in the form of a film upon the surface of a mechanically propelled carrier, and while in such condition and in motion, the film of material is heated to the required temperature and exposed tothe action of a drying atmosphere circulated into contact with said film for evaporating the moisture content thereof.

In the form of apparatus adapted for carrying out the invention, the mechanically propelled carrier is an endless apron supported by suitable means Within a chamber, the latter having an inlet for the drying atmosphere and an exit for said atmos-- phere laden more or less with moisture evaporated from the semiliquid material on said carrier apron. Cooperating with said carrier apron are battles which produce flow channels of relatively narrow cross sectional area, and within such flow channels are positioned heaters that are in the line of flow of the drying atmosphere, the latter circulating freely into contact with the film of material upon the surface of the carrier apron.

The flow of the drying atmosphere is in a direction contrary to the direction of than;

movement of the film upon the surface of the endless carrier, said atmosphere being supplled to the chamber at the temperature "of the outside air, as a result of which the air admitted initially to the chamber has a tendency to cool, or partially cool, the

dried material upon the endless carrier at or adjacent the delivery end thereof, and the drying atmosphere circulated into contact with the heated material becomes partially heated by such contact, the air flowing within the flow channels so as to be heated to the desired temperature by heating coils within said flow channels.

The apparatus is automatic in operation, requiring no attendance of labor, for the reason that the feed of the material and its distribution in a film upon the conveyor apron are effected mechanically, whereas the speed, volume and velocity of the drymg atmosphere are dependent upon the operation of a blower, and the temperature control is obtained by suitable mechanism, thereby resulting in an apparatus adapted for the production of a dry powder on a commercia scale, which apparatus is economical in construction and operation, and the product is handled wholly by mechanicalappliances and under hygienic conditions free from contact With human hands.

Other functions and advantages of the invention will appear from the following description taken in connection with the drawings, whereinliigure 1 is a vertical longitudinal section, an

Figure 2 is an enlarged detail view of one of the drums for the endless carrier;

A designates the movable carrier, herein shown as an endless apron composed of suitable material, such as wiregauze of small mesh, fabric, or other material suitable for the purpose. Said apron is positioned within a housing or casing B, the same being provided with an inlet G for the drying atmosphere and with a stack or flue D for the outlet of the atmosphere, laden more or less with moisture evaporated from the material. The drying atmosphere, usually air, is circulated within the housing by the action of a blower C, the outlet of which is in communication with the intake G of the casing, see Figure 1. The apron is supported on barrels, drums orsprocket wheels at, a, one

TUE?

as a stay or stop, see Fi ure 2, in which.

case one of the shafts a is provided with sprockets the rims of which has a pocket or pockets b within which the slat o'r slats b are adapted to work.

E F are bafiies positioned within the easing or housing and in coo erative relation to the upper and lower lea s of the endless a ron, said bafiies extendin longitudinally o the casing and being inc ined therein at angles corresponding to the angles of inclination of the upper and lower leads of said apron. The bafiies are thus positioned parallel to the leads of the apron, and produ'ce therewith flow channels E F next to said apron, and within said channels is adapted to circulate the drying atmosphere, the velocity, volume and capacity of which is determined by the action of a fan or blower (not shown), whereby the drying atmosphere flows into contact with the material on the outer surfaces of the apron.

Positioned within said flow channels E F are heaters G H, herein shown as coils for the circulation of steam, air, water or other heating medium, although it may be desirable to utilize electric heaters. The heating coils are of desired radiating capacity, and they are shown as extending longitudinally within the flow channels, said coils being co-extensive with the leads of the apron and parallel therewith.

For securing a desired flow of the drying atmosphere into intimate contact with the material on the conveyer apron, and into contact also with the heaters, I provide the transverse ba-flies I J, the latter being positioned crosswise within the flow channels and transversely to the heating coils, said transverse baflles being ositioned in staggered or alternate relation or the purpose of divert ing the flow of the drying atmosphere so as to direct it toward the material on the apron and the heating pipes, whereby the drying atmosphere is heated to a temperature desired for exchanging heat for moisture.

Suitable means are provided for feeding the semi-liquid materia to the carrier apron, the same being shown as a hopper or trough K positioned close to the surface of the apron at the end where said apron is exposed outside of the housing B, see Figure 1.

Means are provided for effecting the deor scraper L tion within the flow channel F.

tachment of the dried material from the apron, said means being shown as a knife ositioned in close relation to the path of tie apron at the point where said a ron is fitted to the barrel or sprockets a, see igure 1.

In 0 eration, the barrel or sprockets a are rotated for imparting motion to the-apron, steam is admitted to the heaters, the blower feeds air at atmospheric'temperature to the flow channel F, and the liquid material is deposited in a relatively thin film on the surface of the apron. The apron carries the material within the flow channels, whereas the air is circulated in an opposite direction to the direction of movement of the filni. The air flowing within the flow channels is heated by the coils and directed by the transverse baflies into contact with the material, effecting the exchange of heat for moisture so as to evaporate the aqueous content of the material. The drying atmosphere laden with moisture more or less flows out of the exit-D, but the inflowing air admitted at the inlet flows into contact with the warm material adjacent the delivery and of the apron, thus measurably reducing the temperature of the dry material and imparting some heat to the an as it begins its circula- The air circulates into intimate contact With the heating coils and with the film of material, so that the coils heat the air to the required temperature, and as the material'is exposed as a thin film and for the considerable area afiorded by the endless apron the product is dried as it moves in the long path provided by the flow channels E F, the dried product being detached from the apron by the scraper.

Havingthus fully described the invention, what I claim as new and desire to secure by Letters Patent, is:

1. In an apparatus for treating liquid and i semiliquid materials, a chamber, an endless carrier movable within said chamber, an end portion of said carrier being exposed to access exteriorly of said chamber, means for feeding to the exposed part of the carrier material in a film-like condition, bafiies within the chamber and adjacent the carrier for producing a succession of flow channels, heating means positioned substantially centrally within the flow channels, transverse baflies also within the flow channels, said transverse baflles being staggered relatively to the carrier and the first named bafiies, said two series of battles being disposed alternately adjacent upper and lower boundaries of the flow channels, an outlet from the chamber at one end of the flow channels,said outlet for the drying atmosphere being adjacent the point at which the material is fed to the. exposed part of said carrier,

- means for feeding atmospheric air at normal temperature to the flow channel adjacent the point of egress of material from said chamber, whereby the inflowing cool air is conducted into contact with the heated product upon said carrier for reducing the temperature of said product, and means for circulating air within the flow channels in a direction contrary to the direction of movement of said material.

2. An apparatus for treating liquid materials and semi-liquid materials embodying a housing, a carrier movable therein, said carrier being in opposing relation to the walls of the housingand forming therewith a succession of flow channels, heating means positioned substantially centrally within the flow channels, transverse bafiles disposed alternately adjacent upper and lower bound aries of the How channels, means for feeding the material to said carrier, and means for circulating a drying atmosphere within the flow channels.

.3. An apparatus for treating liquid materials and semi-liquid materials embodying a housing, and endless carrier the leads or runs of which are positioned in opposing relation to the walls of said housing and forming therewitha succession of flow channels,

transverse baffles disposed alternately adjacent upper and lower boundaries of the flow channels, heating means positioned substantially centrally within said flow channels and crossing the planes of the baffles, and means for circulating a drying atmosphere within the flow channels and into contact with said bafiles and with the leads or runs of said carrier.

4. In the art of concentrating liquid or semi-liquid materials, the process which consists in moving a film of material within a circulatory path having an inlet and an outlet for such material, feeding to the circulatory path a drying current of at mospheric air, circulating such drying current of atmospheric air within the circulatory path and in a direction contrary to the movement of the film of material and into contact therewith, repeatedly heating the drying current of atmospheric air as it flows within said circulatory path to maintain such drying current at a temperature less than the temperature of the film of material, and diverting the course of the drying current within the circulatory path to direct such current into repeated alternate contacts with the moving film of material and with heating surfaces.

In testimony whereof I have signed my name hereto this 11th day of October, 1920.

GORDON DON HARRIS. 

